This invention relates to a driving circuit, used together with a flash lamp supplied with an exciting voltage, for energizing a laser device in response to a trigger pulse.
A driving circuit for energizing a laser device, which may be a solid-state laser device comprises a discharge source circuit and a trigger circuit and is used together with a flash lamp having a pair of discharge electrodes and disposed adjacent to the laser device. The discharge source circuit is to be connected to the electrodes so as to supply an exciting voltage thereacross. The trigger circuit comprises a trigger pulse source for producing a trigger pulse, a transformer for developing a high voltage pulse across a pair of output terminals thereof in response to the trigger pulse, and an exciting member disposed so as to surround the lamp and to be connected to one of the lamp electrodes for causing a discharge to occur between the electrodes in response to the voltage pulse. The laser device is energized by the discharge to produce a pulse laser beam.
As will later be described with reference to one of a few figures of the accompanying drawing, a conventional driving circuit of the type described allows an inevitable self-flashing, or a parasitic discharge, to occur in the lamp due to a parasitic voltage developed across the output terminals as a result of the discharge. To suppress the parasitic voltage, an alternative conventional driving circuit is provided with an expensive element, such as an ignitron, in the discharge source circuit as will also later be described with reference to another figure of the accompanying drawing. The switching element is controlled by a complicated control circuit. This renders the driving circuit more expensive.